# CVE-2023-42115: exim4: Exim AUTH Out-Of-Bounds Write Remote Code Execution Vulnerability

CVE-2023-42115 is fixed in 6 products on 1 platform, first by exim4 4.93-13ubuntu1.8, released September 27, 2023. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2023-42115
- Priority: High
- CVSS: 9.8 (Medium)
- EPSS: 0.1219
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 27, 2023

## Description

Exim AUTH Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Exim. Authentication is not required to exploit this vulnerability. The specific flaw exists within the smtp service, which listens on TCP port 25 by default. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of a buffer. An attacker can leverage this vulnerability to execute code in the context of the service account. . Was ZDI-CAN-17434.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | exim4 Debian 12.15 (bookworm) | 4.96-15+deb12u2 | [DEBIAN-CVE-2023-42115](https://patchblox.com/security/data/fix/linux/debian-cve-2023-42115.md) | May 3, 2024 |
| Linux | exim4 Debian 13.5 (trixie) | 4.97~RC1-2 | [DEBIAN-CVE-2023-42115](https://patchblox.com/security/data/fix/linux/debian-cve-2023-42115.md) | May 3, 2024 |
| Linux | exim4 Debian 14 | 4.97~RC1-2 | [DEBIAN-CVE-2023-42115](https://patchblox.com/security/data/fix/linux/debian-cve-2023-42115.md) | May 3, 2024 |
| Linux | exim4 Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.8 | [exim4 4.93-13ubuntu1.8](https://patchblox.com/security/data/fix/linux/ubuntu-focal-exim4-4.93-13ubuntu1.8.md) | Sep 27, 2023 |
| Linux | exim4 Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.3 | [exim4 4.95-4ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-exim4-4.95-4ubuntu2.3.md) | Sep 27, 2023 |
| Linux | exim4-base Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.8 | [exim4-base 4.93-13ubuntu1.8](https://patchblox.com/security/data/fix/linux/ubuntu-focal-exim4-base-4.93-13ubuntu1.8.md) | Sep 27, 2023 |
| Linux | exim4-base Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.3 | [exim4-base 4.95-4ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-exim4-base-4.95-4ubuntu2.3.md) | Sep 27, 2023 |
| Linux | exim4-config Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.8 | [exim4-config 4.93-13ubuntu1.8](https://patchblox.com/security/data/fix/linux/ubuntu-focal-exim4-config-4.93-13ubuntu1.8.md) | Sep 27, 2023 |
| Linux | exim4-config Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.3 | [exim4-config 4.95-4ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-exim4-config-4.95-4ubuntu2.3.md) | Sep 27, 2023 |
| Linux | exim4-daemon-heavy Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.8 | [exim4-daemon-heavy 4.93-13ubuntu1.8](https://patchblox.com/security/data/fix/linux/ubuntu-focal-exim4-daemon-heavy-4.93-13ubuntu1.8.md) | Sep 27, 2023 |
| Linux | exim4-daemon-heavy Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.3 | [exim4-daemon-heavy 4.95-4ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-exim4-daemon-heavy-4.95-4ubuntu2.3.md) | Sep 27, 2023 |
| Linux | exim4-daemon-light Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.8 | [exim4-daemon-light 4.93-13ubuntu1.8](https://patchblox.com/security/data/fix/linux/ubuntu-focal-exim4-daemon-light-4.93-13ubuntu1.8.md) | Sep 27, 2023 |
| Linux | exim4-daemon-light Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.3 | [exim4-daemon-light 4.95-4ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-exim4-daemon-light-4.95-4ubuntu2.3.md) | Sep 27, 2023 |
| Linux | eximon4 Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.8 | [eximon4 4.93-13ubuntu1.8](https://patchblox.com/security/data/fix/linux/ubuntu-focal-eximon4-4.93-13ubuntu1.8.md) | Sep 27, 2023 |
| Linux | eximon4 Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.3 | [eximon4 4.95-4ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-eximon4-4.95-4ubuntu2.3.md) | Sep 27, 2023 |

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